1. Technical Field
The invention relates to customer purchase behavior. More particularly, the invention relates to a product space browser.
2. Description of the Prior Art
Retail leaders recognize today that the greatest opportunity for innovation lies at the interface between the store and the customer. The retailer owns vital marketing information on the purchases of millions of customers: information that can be used to transform the store from a fancy warehouse where the customer is a mere stock picker into a destination where customers go because of the value the store gives them. The opportunity is enormous: seventy to eighty percent of buying choices are made at the point of purchase, and smart retailers can influence the choices to maximize economic value and customer satisfaction. Because the retailer is closest to the consumer, he has the unique opportunity and power to create loyalty, encourage repeat purchase behavior and establish high value purchase career paths. However, to optimize the customer interface in this fashion, retailers must be extremely sophisticated with analysis of their purchase data. The sheer volume of purchase data, while offering unprecedented opportunities for such customer centric retailing, also challenges the traditional statistical and mathematical techniques at the retailer's disposal. Retail data analysts frequently find it difficult, if not impossible, to derive concrete, actionable decisions from such data. Most traditional retailers use only limited OLAP capabilities to slice and dice the transaction data to extract basic statistical reports and use them and other domain knowledge to make marketing decisions. Only in the last few years have traditional retailers started warming up to segmentation, product affinity analysis, and recommendation engine technologies to make business decisions. Traditional computational frameworks, such as classification and regression, seek optimal mappings between a set of input features that either cause or correlate-with a target variable. It would be advantageous to provide improved approaches to retail data mining.
A Model of the Retail Behavior of Customers
Customer purchase behavior may be characterized as a mixture of projections of time-elapsed latent purchase intentions. A customer purchases a particular product at a certain time in a certain store with a certain intention, e.g. weekly grocery, back-to-school, etc. An intention is latent, i.e. it is not obvious or announced, although it may be deduced from the context of the products purchased. Each visit by a customer to the store may reflect one or more (mixture of) intentions. Each intention may involve purchase of one or more products. For a multi-product intention, it is possible that the customer may not purchase all the products associated with that intention either at the same store or in the same visit. The transaction data only reflects a subset or a projection of a latent intention for several reasons, for example, maybe the customer already has some of the other products associated with the intention, or he received them as a gift, or he purchased them at a different store, etc. Finally, an intention may be spread across time. For example, certain intentions, such as kitchen remodeling or setting up a home office, may take several weeks and multiple visits to different stores.
A Model of Retail Transaction Data
Retail transaction data may be characterized as a time-stamped sequence of market baskets. The key characteristics of such a transaction data are:                Noisy—both intentional and impulsive purchases;        Incomplete—only projections of intentions present;        Overlapping—mixture of intentions in the same visit;        Indirect—purchase drivers or customer intentions are latent;        Unstructured—customers have different length time histories; and        Time-component—patterns in the data elapse along time.        
These characteristics pose challenges in discovering consistent and significant patterns of purchase behavior from transaction data that may be used for making precise, timely, and profitable decisions by retailers.